1983 Mazda RX-7 GSL - When Opposites Attract

If Mazda and Honda Got Busy, This is What Would Happen

Look hard, but you won’t find Mazda’s early 1980s, first-generation RX-7s 12A on anyone’s best-engines-of-all-time list. Ask 1983 and it might tell you otherwise, but 30 years of fuel injection, turbocharger and metallurgy advancements will prove 1983 wrong every time. And so will Socheat Ngoun who brushed off Mazda’s early rotary not for the later-model, twin-turbo Wankel that you think he did, but for something altogether different. Something outside of any engine swap rulebook. Something that was bound to piss off both Mazda and Honda purists alike. Something like the S2000’s naturally aspirated F-series.

The RX-7 and Honda’s anniversary celebratory roadster are about as incompatible with one another as cars from two entirely different makes often are. It’s true that both are built off of rear-wheel-drive platforms, but aside from whatever other obvious similarities there are, any likeness ends there. All of this means that fitting the F22C1 under the Mazda’s hood and mating it with the car’s native ancillaries and rear differential wasn’t easy. One-off engine mounts are only the beginning. The RX-7’s drivetrain, as well as its fuel, cooling and electrical systems are all a multi-decade-spanning homologation between the two Japanese automakers.

The F-series wasn’t necessarily meant to be, though. After scoring the chassis from a relative, Chevy’s eight-cylinder LS1 seemed like the obvious swap. “The car came with a stock 12A rotary, which was too slow for me,” Socheat says. “The first thing that came to my mind was an LS1 swap because [my brother] has an FC [RX-7] with one.” It’s his brother who’d suggested a swap, only he had an entirely different engine in mind: Honda’s twin-cam F-series. Socheat’s automotive roots took shape driving almost anything bearing the VTEC flag, which made the choice an easy one and, in part, led his brother’s suggestion to reality.

Retrofitting Honda’s 2.2L, rear-wheel-drive powertrain in place of the 12A rotary is far from realistic though, and as it turns out, nearly every tuning shop in the greater San Francisco area agreed. “After finding the motor, no one wanted to do the swap,” Socheat says. No one except for nearby Stockton’s West Lane Muffler who fabricated the engine and transmission mounts and built a driveshaft that makes use of the factory S2K gearbox. The S2000 paraphernalia doesn’t end with the engine and trans. Electronics addenda are also borrowed from the two-seater. AEM’s Series Two engine management system calls the shots and syncs up with the chassis with the help of an S2000 instrument cluster rendered to fit within the Mazda cabin. It’s all very much a Honda-themed union, and that’s perfectly all right with Socheat, who’s owned everything from a series of fifth-generation Civics to a bona fide S2000. He says of his former Honda ensemble, “you can call me a Honda guy.” He goes on to address any of Mazda’s ilk who might not forgive such a swap: “Who cares? I love VTEC [laughs].”

It’s taken nearly two years but Socheat’s home-brewed hybrid sits exactly how he saw fit all along. Techno Toy Tuning—a firm specializing in making odd swaps work—was called upon for its coilover-conversion kit and adjustable camber plates, but it’s the Mugen M7 wheels you’ll notice once you’ve gotten past dressing down the engine. The Honda motif spills indoors where a wood-grain Mugen steering wheel’s perched above the company’s shift knob and a Civic Type R shift boot. Underneath the hood, the engine remains lightly modified with Supertech valvetrain and a Weapon-R intake system. The mods are all simple yet effective and leave almost no indication as to what exactly lies underneath the hood.

Almost. So says Socheat: “To get the JDM heads mad and call me a ricer, I added a cute, little DOHC VTEC sticker in the rear just to see them laugh when we’re at the light.”

Honda’s F-series nomenclature dates back to the 1990 Accord, but it wasn’t until the S2000’s introduction for the 2000 model year that a proper twin-cam version was introduced. To be fair, the two share little in common beyond bore spacing and surnames. First available as a 2.0L, the F20C1 served as a foreshadowing predecessor to the company’s soon-to-be successful lineup of K-series engines before receiving a minor stroke alteration that led to a slightly larger 2.2L version. The S2000’s F-series carried over Honda’s VTEC architecture but remains among the first to employ a roller rocker valvetrain and chain-driven architecture—both distinguishing elements of the K-series. Both the F20C1 and F22C1 are also among the very few longitudinally mounted, rear-wheel-drive-native, four-cylinder engines the company’s ever produced. Output differs little between the two, but only the F20C1 laid claim to generating the highest specific power output of any naturally aspirated production engine, measuring in at 123.5hp per liter. The Ferrari 458 Italia and Porsche’s 911 GT3 RS 4.0 have since bested the S2000 but by no more than a mere 1.5hp at the expense of exponentially more dollars. More than a decade after its initial production run, Honda’s DOHC F-series remains one of the company’s most impressive four-cylinder powerplants to date and should be remembered for introducing technology that’s since made its way throughout much of the company’s present-day engine line.